/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "ImageLogging.h"  // Must appear first
#include "gfxPlatform.h"
#include "jxl/codestream_header.h"
#include "jxl/decode_cxx.h"
#include "jxl/types.h"
#include "mozilla/TelemetryHistogramEnums.h"
#include "mozilla/gfx/Point.h"
#include "nsJXLDecoder.h"

#include "RasterImage.h"
#include "SurfacePipeFactory.h"

using namespace mozilla::gfx;

namespace mozilla::image {

#define JXL_TRY(expr)                        \
  do {                                       \
    JxlDecoderStatus status = (expr);        \
    if (status != JXL_DEC_SUCCESS) {         \
      return Transition::TerminateFailure(); \
    }                                        \
  } while (0);

#define JXL_TRY_BOOL(expr)                   \
  do {                                       \
    bool succeeded = (expr);                 \
    if (!succeeded) {                        \
      return Transition::TerminateFailure(); \
    }                                        \
  } while (0);

static LazyLogModule sJXLLog("JXLDecoder");

nsJXLDecoder::nsJXLDecoder(RasterImage* aImage)
    : Decoder(aImage),
      mLexer(Transition::ToUnbuffered(State::FINISHED_JXL_DATA, State::JXL_DATA,
                                      SIZE_MAX),
             Transition::TerminateSuccess()),
      mDecoder(JxlDecoderMake(nullptr)),
      mParallelRunner(
          JxlThreadParallelRunnerMake(nullptr, PreferredThreadCount())) {
  JxlDecoderSubscribeEvents(mDecoder.get(),
                            JXL_DEC_BASIC_INFO | JXL_DEC_FULL_IMAGE);
  JxlDecoderSetParallelRunner(mDecoder.get(), JxlThreadParallelRunner,
                              mParallelRunner.get());

  MOZ_LOG(sJXLLog, LogLevel::Debug,
          ("[this=%p] nsJXLDecoder::nsJXLDecoder", this));
}

nsJXLDecoder::~nsJXLDecoder() {
  MOZ_LOG(sJXLLog, LogLevel::Debug,
          ("[this=%p] nsJXLDecoder::~nsJXLDecoder", this));
}

size_t nsJXLDecoder::PreferredThreadCount() {
  if (IsMetadataDecode()) {
    return 0;  // no additional worker thread
  }
  return JxlThreadParallelRunnerDefaultNumWorkerThreads();
}

LexerResult nsJXLDecoder::DoDecode(SourceBufferIterator& aIterator,
                                   IResumable* aOnResume) {
  // return LexerResult(TerminalState::FAILURE);
  MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");

  return mLexer.Lex(aIterator, aOnResume,
                    [=](State aState, const char* aData, size_t aLength) {
                      switch (aState) {
                        case State::JXL_DATA:
                          return ReadJXLData(aData, aLength);
                        case State::FINISHED_JXL_DATA:
                          return FinishedJXLData();
                      }
                      MOZ_CRASH("Unknown State");
                    });
};

LexerTransition<nsJXLDecoder::State> nsJXLDecoder::ReadJXLData(
    const char* aData, size_t aLength) {
  const uint8_t* input = (const uint8_t*)aData;
  size_t length = aLength;
  if (mBuffer.length() != 0) {
    JXL_TRY_BOOL(mBuffer.append(aData, aLength));
    input = mBuffer.begin();
    length = mBuffer.length();
  }
  JXL_TRY(JxlDecoderSetInput(mDecoder.get(), input, length));

  while (true) {
    JxlDecoderStatus status = JxlDecoderProcessInput(mDecoder.get());
    switch (status) {
      case JXL_DEC_ERROR:
      default:
        return Transition::TerminateFailure();

      case JXL_DEC_NEED_MORE_INPUT: {
        size_t remaining = JxlDecoderReleaseInput(mDecoder.get());
        mBuffer.clear();
        JXL_TRY_BOOL(mBuffer.append(aData + aLength - remaining, remaining));
        return Transition::ContinueUnbuffered(State::JXL_DATA);
      }

      case JXL_DEC_BASIC_INFO: {
        JXL_TRY(JxlDecoderGetBasicInfo(mDecoder.get(), &mInfo));
        PostSize(mInfo.xsize, mInfo.ysize);
        if (mInfo.alpha_bits > 0) {
          PostHasTransparency();
        }
        if (IsMetadataDecode()) {
          return Transition::TerminateSuccess();
        }
        break;
      }

      case JXL_DEC_NEED_IMAGE_OUT_BUFFER: {
        size_t size = 0;
        JxlPixelFormat format{4, JXL_TYPE_UINT8, JXL_LITTLE_ENDIAN, 0};
        JXL_TRY(JxlDecoderImageOutBufferSize(mDecoder.get(), &format, &size));

        mOutBuffer.clear();
        JXL_TRY_BOOL(mOutBuffer.growBy(size));
        JXL_TRY(JxlDecoderSetImageOutBuffer(mDecoder.get(), &format,
                                            mOutBuffer.begin(), size));
        break;
      }

      case JXL_DEC_FULL_IMAGE: {
        gfx::IntSize size(mInfo.xsize, mInfo.ysize);
        Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
            this, size, OutputSize(), FullFrame(), SurfaceFormat::R8G8B8A8,
            SurfaceFormat::OS_RGBA, Nothing(), nullptr, SurfacePipeFlags());
        for (uint8_t* rowPtr = mOutBuffer.begin(); rowPtr < mOutBuffer.end();
             rowPtr += mInfo.xsize * 4) {
          pipe->WriteBuffer(reinterpret_cast<uint32_t*>(rowPtr));
        }

        if (Maybe<SurfaceInvalidRect> invalidRect = pipe->TakeInvalidRect()) {
          PostInvalidation(invalidRect->mInputSpaceRect,
                           Some(invalidRect->mOutputSpaceRect));
        }
        PostFrameStop();
        PostDecodeDone();
        return Transition::TerminateSuccess();
      }
    }
  }
}

LexerTransition<nsJXLDecoder::State> nsJXLDecoder::FinishedJXLData() {
  MOZ_ASSERT_UNREACHABLE("Read the entire address space?");
  return Transition::TerminateFailure();
}

}  // namespace mozilla::image